Method of making magnetic materials.



'ment.

between 700 and 800 centigrade, then roll UNITED PATENT oFFIon ROBERTA. HADFIELD, o F SHEFFIELD, ENGLAND.

METHOD'OF MAKING NIAGNEITIC MATERIALS.

- Specification of Letters Patent; Application fi1ed Ju1y-5, 1908. Serial No. 324,897,

' Patented Nov. 2-7 1906.

Too/ll whom it may concern:

Be it known that I, ROBERT ABBOTT HA FIELD, a subject of the King of Great Britain,

residing at Sheffield, England, have invented 1 Improvement in of a certain new and use Methods of Making Magnetic Materials,

I which the following is a specification.-

In United States Letters Patent No.-

767,110, granted to me August 9, 1904, I' have descr'bed and claimed a method of p said alloy is really heated three times-that is to say, once before mechanical treatment and twice afterward.

In carrying my present process into effect I eliminate one of these subsequent heat treatments, or rather substitute for it the preliminary heating before mechanicaltreat- Thus I first heat the material to, say,

treated, and hence the it or otherwise mechanically reduce it to a thin sheet, then reheat to between-900 and 1,000 centigrade, and finally cool.

'1'. The method of producing a magnetic material of high permeability and low hys- 'teresis action, which consists in alloying a magnetic substance with silicon, heating said substance to a tem erature below its meltingoint, mechanical y treating said substance to reduce it to a sheet, reheating said sheet to a temperature below its melting-point, and different and finally-cooling.

2. The method of producing a magnetic from said first-named temperature,

material of high permeability andlow hysteresis action, which magnetic substance with silicon, heating said substance to a temperature below its melting-point, mechanically treating said subconsists in alloying'a stance to reduce -it to a sheet, reheating said ,sheet to a temperature below its meltingpoint but above said first-named temperature, and finally coolin In witness whereof I have signed my name hereto in the presence of two witnesses;

ROBERT A. HADFIELD.

Witnesses HENRY E. DIXON, FRANK HUTson, 

